coefficient of expansion
Học thuậtThân thiện
Definition
Noun: A numerical value that quantifies how much a material's length, area, or volume changes per degree of temperature change, measured under constant pressure. It describes the tendency of a substance to expand when heated or contract when cooled.
Usage
The term is used in physics, engineering, and materials science to specify and compare the thermal expansion properties of solids, liquids, and gases. It is a critical parameter for designing structures, components, and systems that experience temperature variations.
Examples
- Engineers must account for the coefficient of expansion when designing bridges to prevent structural damage from seasonal temperature changes.
- The coefficient of expansion for glass is much lower than that for most metals, which is why glass can crack if heated too quickly.
- In the lab, we calculated the coefficient of expansion by measuring the change in the rod's length as we increased the temperature.
Advanced Usage
- Linear Coefficient of Expansion: Specifically refers to the fractional change in per degree of temperature change.
- Area Coefficient of Expansion: Refers to the fractional change in per degree of temperature change.
- Volumetric Coefficient of Expansion: Refers to the fractional change in per degree of temperature change. For isotropic solids, it is approximately three times the linear coefficient.
Variants and Related Words
- Thermal Expansion Coefficient: A synonymous term.
- Expansivity: Another term for the coefficient of expansion.
- Alpha (α): The common symbol for the linear coefficient of expansion.
- Beta (β): The common symbol for the area coefficient of expansion.
- Gamma (γ): The common symbol for the volumetric coefficient of expansion.
Synonyms
- Thermal expansivity
- Expansivity coefficient
Notes
The "coefficient of expansion" is not typically used in idiomatic expressions or phrasal verbs, as it is a precise technical term. Its value is usually constant only over a specified temperature range for a given material.
Noun
- the fractional change in length or area or volume per unit change in temperature at a given constant pressure